Proposals have been put forward for the £2 million facility at St Magnus Cathedral, founded in 1137 at Kirkwall, Orkney.
But locals fear the ramp, the removal of a 100-year-old door and the installation of a new glass entrance will change the look of the building.
Councillor John Ross Scott has come under fire for backing the plans, funded by voluntary group the Society of the Friends of St Magnus Cathedral.
If approved, the plans will see a raised walkway from the Palace Road side of the cathedral towards the main entrance.
As part of the works an interior doorway, fitted in 1926, will be removed and a glass entrance fitted to the interior of the ancient building.
But the plans, by Orkney Islands Council, are now at the centre of a row, with locals accusing Mr Scott of riding roughshod over objections based on concerns about changing the look of the cathedral.
Mr Scott is an adviser to the Society of the Friends of St Magnus Cathedral appointed by Orkney Islands Council.
On social media, islander Aine King said to Mr Scott: “Dismissing objections as merely ‘negative’ is very worrying. This kind of imbalance just pours more fuel on the fire of people’s sense of powerlessness and disenfranchisement.
“You’re well on your way to establishing a situation where anyone raising any objection is a ‘troll’ or ‘rubbish’. You are being a bully.”
Mr Scott said: “I am not a bully, I am shooting from the hip, as I always do.
“Most people do not like change but this – in my view and others involved in conservation – the plans are a change for the better and will also involve much needed repairs to the cathedral’s West Door.
“I know how hard the Friends have worked to get these changes, and as Depute Front of House at St Magnus Festival I know how many folk in wheelchairs struggle to get through the south door.
“This building is a gem in Orkney’s crown and people should have access to it. Don’t bark about change through ignorance. Do not let the ‘Friends’ down.”
A spokeswoman for Orkney Island Council said: “We are aware that the cathedral story generated some very active discussion on social media.
“We have not received any complaints from members of the public in regards to this.
“The Standards Commission for Scotland has set out a Councillors Code of Conduct outlining the standards of conduct expected of councillors – should any person feel that these standards have not been met by an elected member then they are free to make their concerns known.”